# A152364 (b-file synthesized from sequence entry) 1 1 2 2 3 6 4 24 5 120 6 720 7 4416 8 31416 9 244848 10 2051440 11 19937544 12 199909750 13 2216470260 14 25839182598 15 333498017906 16 4555645851472